Process of making chloroform



are. 753,325.

,UNITED STATES Patented March'l, 1904.

PATENT. OFFICE.

ALBERTW. SMITH, o-F CLEVELAND, oHIo.

' PRooEs'S- OF MAKING oHtonoFoRm,

TSPEOIFIGATIQN forming part of Letterslatent No. 753,325, dated March 1,1904.

Application filed October 9, 1902- Serial No. 126,451- (No specimens-lTo all whom it may concern:

Be it known thatI, ALBERT W. SMITH, a citizen of the United States, anda resident of Cleveland, county of Cuyahoga, and State of Ohio, haveinvented a new and useful Improvement in Processes of Manufacturing"Chloroform, of which the following is a specification, the principle ofthe invention being herein explained and the bestmode iri which I havecontemplated applying that principle,

' so as to distinguish it from other inventions.

My improved process relates to the,-manufacture of chlordform,'itsobject being to produce the same in a manner more economical than thoseof the processes of production generally used at present and at the sametimeto produce a product'purer than that produced by the presentcommercial process from acetone and chlorid of lime in that itcoiitainsno dangerous andpoisonous oxygen compounds, from which the latter mustbe carefully freed.

Said invention consists of certain steps hereinafter fully described,and specifically set forth in-the claims, such, description settingforth in-detail one mode of carrying out the invention and suchdisclosed mode constitut ing but one of various ways in which theprinciple of the invention may be used- My improved process consists inthe pro-' duction ofchloroform by the following steps,

"including the action of heated sulfur upon heated'carbon, so astoproduce carbon 'bisulfid, theactlon of chlorin upon sulfur, so as toproduce sulfur chlorid or .dichlorid, the action of sulfur chlorid ordichloridupon carbon bisulfid, so as to. produce carbon tetrachlorid,and, finally, the reduction of the carbon tetrachlorid, so as to producechloroform. Thecarbon'bisulfid may be produced by any of the well-knownmethods, such as by heating charcoal with-sulfur in iron retorts or'bypassing sulfur-vapor into a'properly-arranged re- -tort filled withcharcoal and heated internally fyingthe carbon bisulfied.

The sulfur chlorid is best prepared by passing chlorin into a solutionof sulfur in sulfur by an electric current and'subsequently puri--chlorid and adding more sulfur as'that pres- .ent beeomesconverte'dinto chlorid. Either 5Q snlfu;

onochlorid or dichlorid may be used,

preferably the latter. The conversion of these two compounds to thecarbon tetrachlorid is accomplished by mixing with the sulfur chlorid ina retort somewhat less than the requisite quantity of carbon bisulfid toeffect its conversion, adding a small quantity of aluminium, offinely-divided iron, or ofanhydrous iron or'aluminium chlorid, and,finally, boiling with a fractioner until the reaction is practically.completed.

For example, to eight hundred pounds of sulfur chlorid (SClz) ina retortare added six cient carbon bisulfid has been added to convert all of thesulfur dichlorid to the monochlorid,

-(SClz to 82012,) distillation is begun, with a fractioner arranged toreturn the sulfur monochlorid to the retort, at the same time theaddition of the carbon bisulfid being continued until the two hundredand fifty pounds are added. By this time most of the carbontetrachlorid, with a little sulfur chlorid and carbon.

bisulfid, has been distilled. and is ready for 1 further purification.The residue in the retort, consisting mainly of sulfur dissolved insulfur monochlorid, is cooled to remove the greater part of the freesulfur, which is then separated and is made available for the productionof more carbon bisulfid and sulfur chlorid, and thus acts -over and overagain as a carrier of the carbon and chlorin to each other.

It isvthus" seen that the" carbon tetrachlorid is i made from theelements ch'lorinand carbon, the cheapest possible raw material for theproduction of chloroform. The carbon tetra- I chloridso produced isfirst purifiedfrom the small quantity of carbon bisulfid that itcontains by boiling it with a small quantity of sulfur monochlorid fortwohours and from 2 the sulfur chlorid by similar boiling withsulfurywhich'converts any sulfur chlorid to' the, .monochlorid. Fromthisi the tetr'achlorid is readilyseparated by fractional; distillation,yielding practicallypure tetrachlorid. In-

stead'of using sulfur chlorid for making carbon tetrachlorid. sulfurmonochlorid, or a so- IOO ' gen into more intimate contact with eachother answers such purpose.

fable difiiculties.

I of the tetrachlorid. to chloroform. This method acids or most otherreduction methods and v possesses the added advantage that it can bereadlly controlled, so that little or no reduction I at a-time, untilfour hundred pounds have been 5 5 large excess of iron is at any timepresent. 1

seventy hours in all, the temperature being kept at about 15 centigrade.The iron is oxi-.

lution of sulfur in carbon bisulfid and chlorin, may beused. Thepurified carbon tetrachlorid is then reduced tochloroform by thesubstitution of one atom of hy drogen for one atom of chlorin in themolecule of tetrachlorid. This may be accomplished in a number of ways,as by treating the tetrachlorid with some substance or substances thatwill generate nascent hydrogen, such as an acid and a metal or an alkaliand zinc or by electrolytic methods. This reaction may be much shortenedin time by bringing the tetrachlorid and acid used in the production ofnascent hydroby the use of a mutual solvent for both tetrachlorid andacid. Ethyl or methyl alcohol I, have found, how-. ever, that mechanicalagitation of the tetrachlorid with the reducingsubstanccs answers thesame purpose to a certain extent and is preferable, because iteliminates the necessity of separating the chloroform from the mutualsolvent, which in practice presents consider- I have also found thatsimple agitation of the tetrachlorid with water and finely-divided iro'nwithout any acid or simply a trace of acid to start thereaction is oneof the most efficient methods of reduction is far cheaper than thatinvolving the use of to dichlormethane takes place. The temperatureduring this reaction must be carefully controlled, as if it is allowedto rise the reaction becomesso vigorous that the product is completelydestroyed by overreduction. For the same reason it' is preferable to addthe iron in successive small portions, so that no One method ofprocedure is as follows: Five hundred pounds of carbon tetrachloridareplaced in an iron cylinder, the latter mounted on an'axle, so that itcan be rotated, and provided with a-hollow jacket, through which watercan be run, so as td accurately a half-pound of hydrocholricacid andfour iron is addedin small quantities, about a pound added. Theagitation is continued until re-- duction is nearly complete for fromforty to dized by the oxygen of the waterjand the chlorin of thetetrachlorid to an oxychlorid of. iron, and a part of the hydrogen ofthe water- ,replaceszi part of the chlorin of the tetra chlorid toproduce chloroform, which is then separated from the other productsbysteam and fractionally distilled to separate it from any unreducedtetrachlorid and other products.

I therefore particularly point out and distinctly claim as my invention7 1. The process of manufacturing chloroform which consists in formingcarbon disulfid by the action of heated sulfur upon heated carbon,forming carbon tetrachlorid by the action of sulfur chlorid upon suchdisulfid, and then treating such tetrachlorid with a metal and asubstance containing hydrogen.

2. The process of manufacturing chloroform which consists in formingcarbon disulbon tetrachlorid and a metal in a suitable receptacle. v

5. The process of manufacturing chloroform which consists in agitatingwater, car-' bon tetrachlorid, and iron in a suitable receptac e. v

Y 6. The process of manufacturing chloroform, which consists in heatingcarbon'tetrachlorid containing carbon disulfid withsulfur and sulfurchlorid, fractionally distilling the product to produce pure carbontetrachlorid and subjecting the resulting product to the action of ametal and drogen..

7. The process of manufacturing chloroform, which consists in heatingcarbon tetrasubstance containing hy- -chlorid containing carbon disulfidwith sulfur and sulfur chlorid, fractionally distilling the product toproduce pure carbon tetrachlorid and subjecting the resulting product tothe action of a metal and water. I

8. The steps in the manufacture of chloro- 'form which consist, intreating heated sul fur with heated carbon, treating the carbondi- .sulfid thus formed with sulfur chlorid with the production of carbontetrachlorid, purifying the tetrachlorid by heating with sulfur andsulfur chloid, and fractionally distilling, and

then lsubjecting it to the action of water and'a meta I a Signed bymethis 7th day of October, 1902.

' ALBERT W. SMITH. Attest: 'f

Gno. W. SAYWELL A. E. MERKEL.

